feat #1187: storage backend integration & UX improvements

[Santosh69]

Fixes #1187

Summary

Added secure file deletion and real-time size fetching to the backend, the backend code now lives in its own dedicated
storage.js module

Checklist

Backend (Secure Storage)

• Secure Deletion: deleteMediaFile ensures strict ownership validation before deletion.
• Metadata: getFileMetadata fetches real file sizes dynamically.

Additional Notes

1. Testing Proposal: Should we add Unit Tests for this new backend logic in a follow-up PR?
2. Delete Strategy: Implements a "File-Only Delete" strategy (removes physical file to save costs, but preserves the Firestore record to prevent accidental metadata/note loss).
3. Commit Structure: I intentionally made the previous commits follow here, for you to separately test the frontend and backend part

Future Work

This PR updates the Storage Page with real data. The Dashboard Widget still uses mock data, should I update that here or in a separate PR?

Part of #1188

[Santosh69]

Hiii @marcgc21 , could you review this.. happy to make any changes or reverts of the Additional notes

[marcgc21]

@KarinePistili I'm worried about this part:

Delete Strategy: Implements a "File-Only Delete" strategy (removes physical file to save costs, but preserves the Firestore record to prevent accidental metadata/note loss).

In theory if for some reason, we delete the file, it shouldn't be removed from the firestore also? I'm trying to think a way in which we wouldn't like to remove it but I can't find it.

Any idea?

[Santosh69]

yeah @marcgc21 felt exactly the same that is why I added as note, because the files might appear when we refresh (sometimes) , but when clicked would show error and not found etc..

we can make change to handle this, Instead of deleting the record, we could Nullify the link.

[Santosh69]

also lmk if you have thoughts on unit tests and dashboard's mock data..

[sonarqubecloud]

Quality Gate failed

Failed conditions
1 Security Hotspot

See analysis details on SonarQube Cloud